MySQL Logging and radacct directory

I'm currently running FreeRADIUS in this setup: Unix authentication with logging to mysql for accounting. What I'm wondering is, I'm currently seeing the occasional message like this: Tue Oct 11 10:06:32 2005 : Error: rlm_radutmp: Logout for NAS sb-ent2 port 24, but no Login record What I'm wondering is, why, if I'm logging accounting to MySQL, are entries showing up in /var/log/radius/radacct/? Shouldn't I be avoiding those entries by logging to mysql? Any thoughts are appriciated, if you need debug, I will get that. Thanks, Curt LeCaptain